sunglint-polyspectra

Correctly generates surface with correct stats from a power spectrum with the same stats. Required inverting the directions of the python fft routines, i.e.: fft -> ifft and vice versa.

git-svn-id: https://svn.ssec.wisc.edu/repos/geoffc/Python/sunglint/cumulantFunctionSimulate@137 f45efd6a-04c6-4179-886d-a06c9f63a260